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Biden said political rhetoric has become "coarse" and "vile" under President Donald Trump

The former vice president also ripped Trump's "phony nationalism"

Washington (CNN)Former Vice President Joe Biden is cranking up his criticism of Donald Trump, saying political discourse in the country has degraded under the President's watch.

Asked for his "blunt take" on Trump at an Axios event in Philadelphia on Wednesday, the former vice president said political discussion has "gotten so coarse, so vile, so, so demeaning, and our children are listening."

Biden referred to recent white supremacist and nationalist rallies as an example.

"Did any one of you ever think that you would see, in one of the historic cities in America, folks coming out from under rocks and out of fields with torches carrying swastikas literally reciting the same, the same exact anti-Semitic bile that you heard and we heard in the '30s?" Biden said, sitting alongside his wife, Dr. Jill Biden.

Biden appeared to refer to Trump's response over the summer to white supremacist protesters in Charlottesville, Virginia, in which the President blamed "many sides" for the violence that left one person dead.

"And then have those that were protesting compared as the moral equivalent to those people? Folks, this is eating at the fabric of this country. ... It is undermining the social fabric of the nation ... this phony nationalism," Biden said. "The reason why the world is (compared) to America is not just because of the exercise of our power, but it's the power of our example," he added. "It's because of who the hell we are."

The Charlottesville protests appear to weigh heavily on the former vice president's mind because this wasn't the first time Biden has taken a shot at Trump for his reaction to the protests. In the weeks after the event, Biden wrote that Americans "are living through a battle for the soul of this nation."

"Today we have an American president who has publicly proclaimed a moral equivalency between neo-Nazis and Klansmen and those who would oppose their venom and hate," Biden wrote in The Atlantic. "We have an American president who has emboldened white supremacists with messages of comfort and support."

Biden's has become increasingly outspoken with his criticism of the President over the last month. At an October event, he called Trump's diplomatic behavior "absolutely bizarre" and said the President "doesn't understand governance." And during a Chicago speech, he warned that the US is "walking down a dark path" under Trump, calling him a "charlatan."

The ratcheting up of rhetoric against Trump comes after Biden told Vanity Fair that he's leaving the door open for a 2020 presidential run.

"I haven't decided to run," he said. "But I've decided I'm not going to decide not to run. We'll see what happens."